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Two New Aspergillus flavus Reference Genomes Reveal a Large Insertion Potentially Contributing to Isolate Stress Tolerance and Aflatoxin Production
- Source :
- G3: Genes|Genomes|Genetics, G3: Genes, Genomes, Genetics, Vol 10, Iss 10, Pp 3515-3531 (2020)
- Publication Year :
- 2020
- Publisher :
- Genetics Society of America, 2020.
-
Abstract
- Efforts in genome sequencing in the Aspergillus genus have led to the development of quality reference genomes for several important species including A. nidulans, A. fumigatus, and A. oryzae. However, less progress has been made for A. flavus. As part of the effort of the USDA-ARS Annual Aflatoxin Workshop Fungal Genome Project, the isolate NRRL3357 was sequenced and resulted in a scaffold-level genome released in 2005. Our goal has been biologically driven, focusing on two areas: isolate variation in aflatoxin production and drought stress exacerbating aflatoxin production by A. flavus. Therefore, we developed two reference pseudomolecule genome assemblies derived from chromosome arms for two isolates: AF13, a MAT1-2, highly stress tolerant, and highly aflatoxigenic isolate; and NRRL3357, a MAT1-1, less stress tolerant, and moderate aflatoxin producer in comparison to AF13. Here, we report these two reference-grade assemblies for these isolates through a combination of PacBio long-read sequencing and optical mapping, and coupled them with comparative, functional, and phylogenetic analyses. This analysis resulted in the identification of 153 and 45 unique genes in AF13 and NRRL3357, respectively. We also confirmed the presence of a unique 310 Kb insertion in AF13 containing 60 genes. Analysis of this insertion revealed the presence of a bZIP transcription factor, named atfC, which may contribute to isolate pathogenicity and stress tolerance. Phylogenomic analyses comparing these and other available assemblies also suggest that the species complex of A. flavus is polyphyletic.
- Subjects :
- Aflatoxin
Aspergillus flavus
QH426-470
Genome
DNA sequencing
03 medical and health sciences
Aflatoxins
Phylogenomics
reference genomes
Genetics
polyphyletic
Molecular Biology
Gene
Genetics (clinical)
Phylogeny
030304 developmental biology
0303 health sciences
Aspergillus
biology
Phylogenetic tree
Base Sequence
030306 microbiology
food and beverages
aflatoxin
phylogenomics
biology.organism_classification
Genome Report
Genome, Fungal
Subjects
Details
- Language :
- English
- ISSN :
- 21601836
- Volume :
- 10
- Issue :
- 10
- Database :
- OpenAIRE
- Journal :
- G3: Genes|Genomes|Genetics
- Accession number :
- edsair.doi.dedup.....51b94b005fe1c5efe4e40fbfb7d49e73